Many surgical procedures involve placing an implant into bone. For example, when fixing a relationship between adjacent bones or bone segments, one common procedure involves driving one or more screws into the bone(s) to serve as an anchoring device for a fixation element, such as a relatively rigid fixation rod. The fixation element can have a predetermined contour that has been designed according to the properties of the target implantation site, and once installed, can hold the bones or bone segments in a desired spatial relationship until desired healing or fusion has taken place.
In many such procedures, the implant can be placed in the bone at a desired location and/or orientation by driving the implant into the bone. In some procedures, it may be necessary to place the implant into a location near the edge of the bone, for example where the bone has a small width or where the implant is being used to anchor the bone to an adjacent bone. However, it is often desirable to not drive an implant into a portion of a bone that is near the edge of the bone because the implant might cause the edge of the bone to fracture and/or the implant may skive off the edge of the bone. Inserting the implant into the desired position can be complicated by a variety of factors, e.g., the adjacent anatomy, the small size of the bone, irregularities in the shape of the bone, etc. In minimally invasive surgeries, which are becoming increasingly popular, the difficulties with accurately locating an appropriate location and orientation for an implant within the bone can be exacerbated. Traditionally, positional determination can be performed by imaging techniques such as X-rays, even during open surgery, but this can require temporary cessation of the procedure and may need to be performed multiple times throughout a single procedure, thereby increasing a risk related to the use of X-rays.
One particularly complex anatomy for inserting a bone implant is the shoulder joint, for example during a glenoid fixation procedure. During traditional glenoid fixation procedures, one or more bone screws are inserted into the shoulder blade adjacent to the glenoid rim. The glenoid rim can be small, difficult to access, and can have an irregular surface, making it difficult for surgeons to insert a screw into the glenoid rim at a location that is far enough away from the edge to prevent the screw from damaging the shoulder blade. Although this procedure is traditionally performed in open surgery, recently there has been a greater demand to provide for a minimally invasive form of glenoid fixation, which further complicates correct placement of the bone screw in the shoulder blade. Another procedure involving complex anatomies that complicate placement of bone implants is a bone block procedure, in which a bone graft is used to reconstruct a joint surface.
Accordingly, there is a need for devices, systems, and methods to facilitate guiding surgical devices such as a bone implant to a desired location and orientation in the bone.